Valve element opening/closing devices have been conventionally known in which a valve element is driven by a motor as a drive source to open and close a flow passage for refrigerant in a refrigerator or the like. For example, in Japanese Patent Laid-Open No. 2000-346225, a valve element opening/closing device is disclosed in which a valve element including a needle valve is advanced and retreated with a screw mechanism to open and close a flow passage into which refrigerant flows.
In the valve element opening/closing device, a turning prevention mechanism for a valve element is provided so that the valve element to which a rotary power of the motor is applied is not rotated. In the above-mentioned Patent Reference, turning of the valve element is prevented by a bearing plate which is protruded from an outer peripheral face of the valve element and engaged with the valve element.
However, in the structure as described in the above-mentioned Patent Reference, a newly separate member is required to prevent turning of the valve element and thus a manufacturing cost of the valve element opening/closing device increases.
Further, the turning prevention mechanism which is described in the Patent Reference, a turning prevention member is protruded from the outer peripheral face of the valve element and the protruded part is restricted to be turned so that turning of the valve element is prevented. Therefore, a size of the valve element opening/closing device is not reduced.